here is the package's link:https://www.npmjs.com/package/watchify
I saw an usage somewhere: "watchify -o js/bundle.js -v -d js/app.js".
I hope to know what dose the '-d' option mean.
According to watchify source code, it gets passed on to browserify, and taken
--debug -d Enable source maps that allow you to debug your files
Watchify uses browserify and includes the argument list for it:
Look at https://github.com/substack/node-browserify#usage
for more information. As Andrey said, it sets up source maps for debugging.